Method and apparatus for lining a shaft in the earth



May 10, 1966 METHOD AND R. w. JENKINS ETAL 3,250,076

APPARATUS FOR LINING A SHAFT IN THE EARTH Filed Dec. 15, 1962 2 Sheets-Sheet l 7/ avg) 22 FIG. 4, EH34 RAYMOND W. JENKINS WILLIAM D. RORAFF INVENTORS ATTORNEYS y 1966 R. w. JENKINS ETAL 3,250,076

METHOD AND APPARATUS FOR LINING A SHAFT IN THE EARTH Filed Dec. 13, 1962 2 Sheets-Sheet 2 5 W m w i M M o E O T W J 2 m w W w. D. w M N A H O l W M /w MW m x Tcevrafi v 0 b mm 2 figxxwk 4% Q A a M m u m m \m w 4 i-a 9 a 3 0 n A k MN m O. & 1E1: ii ....\..-1 .122: u M ET... oooooo o.

United States Patent 3,250,076 METHOD AND APPARATUS FOR LINING A SHAFT IN THE EARTH Raymond W. Jenkins, Anaheim, and William D. Roraif,

Garden Grove, Calif., assignors to The Ralph M. Parsons Company, Los Angeles, Calif., a corporation of California Filed Dec. 13, 1962, Ser. No. 244,465 7 Claims. (Cl. 6141) This invention relates to shaft excavations in the earth and more particularly relates to an improved method and apparatus for lining such an excavation.

Of the many methods that have been proposed for lining a shaft sunk into the earths surface, one of the potentially most promising has been the lowering into the excavation of a plurality of prefabricated concrete caisson sections.

A number of problems have, however, inhibited the satisfactory performance of this method, among them being the physical difficulty of fastening suitable lowering apparatus to the caisson section and detaching it when the section is lowered into place, and the inability to be certain that a good moisture-proof joint is formed between adjacent sections once they have been lowered into place.

According to the present invention, a method and apparatus is provided which enables any number of prefabricated caisson sections to be easily and conveniently lowered into an excavated shaft. The adjacent sections are joined before they are lowered into the shaft so that the joints, and the sections themselves, may be inspected for flaws before they are lowered into the shaft. In accordance with the present invention, the lowermost caisson section is provided with a suitable shoe, and a plurality of novel lowering bars are fastened to the shoe and cooperate with a pluralityof suitable lowering devices such as hydraulic jacks to lower the shoe into the shaft. When the initial section has been lowered a convenient amount the lowering bars are restrained against further downward movement and another section is joined to the initial section and this procedure continued until the shoe rests on the base of'the excavation. The lowering bars are also made in sections so that additions can be made t'o them concurrently. with the addition of further concrete sections. The various sections never tend to pull apart during this operation but rather are forced more closely together, all the tension being borne by the lowering bars, thus preserving the integrity of the sealed joints. There is no need to detach the lowering bars as they can remain in the shaft and even serve to reinforce the completed caisson.

' It is therefore an object of the present invention to provide a novel method and apparatus for forming a lined shaft in the earth.

' It is another object of the present invention to provide a method and apparatus for lowering a plurality of caisson sections into an excavated shaft.

It is also an object of the present invention to provide a method and apparatus utilizing novel lowering bars for lowering a series of caisson sections into an excavated shaft.

These and other objects and advantages of the present invention will become more apparent upon reference to the following description and the attached drawings, in which:

FIGURE 1 is a sectional side elevation showing details of the method and apparatus of the present invention;

FIGURE 2 is a top plan view of the structure of the present invention;

FIGURE 3 is a view similar to FIGURE 1 showing a further state in the performance of the present invention;

FIGURE 4 is an enlarged view taken substantially on lines 4--4 as shown on FIGURE 3;

3,250,076 Patented May 10, 1966 FIGURE 5 is a plan view, partially in section, taken substantially on lines 55 as shown on FIGURE 4;

FIGURE 6 is a side elevation, partly broken away, taken substantially on lines 66 of FIGURE 4;

FIGURE 7 is a plan view partly in section taken substantially on lines 77 as shown on FIGURE 4; and

FIGURE 8 is a sectional detail showing the joint between two adjacent caisson sections and a lifting insert positioned in one of them.

Referring now to the drawings, a shaft 10 of desired depth and diameter is sunk into the earth by any conventional means and provided with a shoulder 12 at its base. A shallow pit 14 having a diameter larger than the shaft 10 is also dug in the earth and provided with a reinforced concrete lining 16. The shaft is at all times kept filled with a suitable drilling fluid to a height above the base of this lining to prevent any possible'collapse of the shaft. At its upper end the lining 16 may join a reinforced concrete pad 18 and at its lower end may be provided with a suitable drain pipe 20. A plurality of metal base plates 22 which serve to support the rest of the apparatus hereinafter described are positioned around the shaft '10 and secured in any suitable fashion to the concrete lining 16. It should be understood that the shallow pit could be dispensed with and the plates 22 mounted on a concrete pad formed on the earths surface. The shallow pit, however, permits more convenient handling of the apparatus and is therefore preferred. I

As may be seen from FIGURE 1, the first of a series of prefabricated, reinforced concrete caisson shell sec- :tions 24 is lowered into the shaft 10 by means to be presently described. This initial section 24 is provided at its lower end with a steel cutting shoe 26 having a conventional inclined lip 28. A seal of the type shown in FIGURE 8 is formed between the shoe and the section to prevent the entrance of moisture into the caisson interior. Attached to the cutting shoe 26 are a plurality of guide shoes 30 which, in their simplest form, may be a single steel plate having an inclined lip which complements the lip 28. The upper portion of each of these guide shoes 30 is provided with a clevis 32 which may be formed inte g-rally or welded thereto. The clevis is attached to the first of a series of lowering bar sections 34 by means of a plurality of bolts 40. Each of the lowering bar sections 34 is provided at one end with clevis bars 36 which may be welded thereto as shown at 38 in FIGURE 4. The clevis bars 36 are connected to the next section 34 by means of the bolts 40 shown in FIGURE 4.

In this manner, a lowering bar of any desired length may be quickly and conveniently fabricated at the site of the shaft, additional bars being continually added as the shell sections are lowered into the shaft. Each lowering bar section 34 is provided with one or more inter mediate jacking pads 42 which preferably comprise a pair of rectangular steel blocks welded to either side of the section 34 as shown at 44 in FIGURE 4. The lower surfaces of both the clevis bars 36 and the intermediate jacking pads 42 are preferably saw-cut square to provide flat jacking surfaces. These jacking surfaces may be spaced any desired distance apart, for example, in one application a separation of 5 feet was found satisfactory.

Each of the lowering bars is designed to cooperate with suitable jacking and supporting apparatus shown in detail in FIGURES 4, 5, 6 and 7. As shown in FIG- URE 2, four such sets of apparatus 46 are provided and thus the shoe 26 is provided with four guide shoes 30 each with its corresponding lowering bar. Each set of apparatus 46 includes a hydraulic jack and an auxiliary supporting device generally indicated at 52. The hydraulic jack is preferably provided with two hydraulic cylinders 54 and 56 in which travel piston rods 58 and 60 respectively in response 'to' changes in hydraulic pressure transmitted to the cylinders in any convenient manner. The cylinders 54 and 56 are suitably bolted to a base plate 62 which, in turn, is bolted to the plate 22. As may best be seen in FIGURE 6, the plate 62 extends in cantilever fashion over a portion of the opening between the lining 16 and the caisson section 24. The plate 62 is provided with a rectangular opening between the cylinders 54 and 56 so that the lowering bar may be passed therethrough. This opening, of course, has a lateral dimension' greater than either the clevis bars or the intermediate jacking pads.

A load platform 64 is fixedly mounted on the tops of the piston rods 58 and 60' and has fastened thereto a pair of rectangular blocks 66 and 68 which are provided with undercut guideways 70 and 72 respectively. A sliding member 74 is suitably mounted on the load platform 64 and in cooperation with the guideways 70 and 72 so that it may be reciprocated towards and away from the forward edge of the plate 64. The plate 64 is provided with a rectangular opening 78 in its forward edge through which the lowering bar may pass. This opening 78 has a lateral dimension greater than that of the clevis bars 36 and intermediate jacking pads 42, so that the load platform 64 does not interfere with the movement of the lowering bar.

The sliding member 74 is also provided with a rectangular opening 80 in its forward edge; however, the lateral dimension of this opening is less than that of the clevis bars or intermediate jacking pads so that when the slider 74 is moved to its forward position, its upper surface will engage the lower surface of the clevis bars or the intermediate jacking pad and thus restrain the lowering bar against downward movement. All of the load platforms 64 may be joined by suitable supporting members 82 to provide added structural strength and to maintain the platforms in proper. alignment. I

Each auxiliary supporting device 52 may comprise first and second vertical members 90 and 92 mounted on the plate 62 and a horizontal member 94 fastened to the members 90 and 92. The member 90 preferably has a rectangular opening formed therein whose base is flush with the top of the plate 94. The member 92 is also provided with an opening whose base is flush with the member 94 so that the remaining upper portions of the member 92 act to guide the travel of a sliding member 96 which is inserted through the rectangular opening in the member 90 and which is adapted to slide on the plate 94. A handle 98 may be attached to the sliding member 96 to facilitate its movement.

The sliding member 96 is bifurcated at its forward end to form an opening which is large enough to permit free movement of the lowering bar therethrough but not large enough to permit passage of the clevis bars or jacking pads. In order to provide a stable and accurate supporting surface, the forward end of the sliding member 96 is provided with a pair of blocks 100 located on either side of the opening. The blocks are provided with a cam surface which cooperates with the lower surface of a bifurcated wedge 102 which is mounted on the sliding member 96 by means of a suitable lead screw system 104 and post 106. Small differences in spacing between the various clevis bars and jacking pads may thus be compensated by moving the wedge 102 forward or backward by means of the lead screw system 104. As may be seen, the sliding member 96 may be moved forward to support the lowering bar so that the jack can be disengaged from the lowering bar and re-engaged at a point on the lowering bar further removed from the shoe 26.

In the operation of the apparatus just described, the initial caisson section 24, together with its attached shoe 26, is positioned over the shaft by means of any suitable conventional equipment. For this purpose, each of the sections are provided with lifting inserts such as those shown at 108 in FIGURE 8. The piston rods 58 and 60 of the hydraulic jack are extended their maximum amount and the sliding member 74 is moved to its forward position on the load platform 64. The caisson section is then lowered until the uper surface of each of the four sliding members 74 engages the lower surface of the clevis bars or intermediate jacking pads of one of the lowering bar sections 34. The four hydraulic jacks are then simultaneously actuated to retract their piston rods so that the caisson section is lowered into the shaft 10. When the piston rods have been fully retracted, the sliding members 96 of the supporting devices 52 are moved forward to engage the lower surfaces of the clevis bars or jacking pads, thus permitting the sliding member 74 of each of the jacks to be moved to its rearward positionso that the piston rods can again be extended.

A second caisson section is then positioned on top of the first and a suitable joint 110 made. As best shown in FIGURE 8, this joint preferably is of the tongue and groove type with integral gasket shoulders for supporting a gasket 112 of any suitable material. As can be seen, the gasket is confined in the annular space formed by the shoulders of the tongue and groove in a manner such that slight movement of the caisson sections or by hydrostatic pressure cannot displace it. After the joint has been made, it may, if desired, be coated with any suitable moistureproof coating. At the same time additional lowering bar sections 34 are bolted to those already in place. The member 74 then again is moved forward to engage one of the jacking surfaces on the lowering bars and the sliding member 96 moved away from engagement with the lowering bars. This process is, of course, repeated over and over again until the required numbers of caission sections have been lowered into the shaft. Each additional caisson section is positioned on top of the preceding section and a suitable joint completed when the preceding section has been lowered sufficiently into the ground. In this Way, all joints can be made and inspected before they are lowered into the shaft and thus good moisture-proofing is assured. The only force acting on the concrete sections is thus a compressive force which they are best able to withstand. All of the tension is borne by the metal lowering rods and thus there is no tendency for the joints, or the sections themselves to be pulled apart.

Once the entire length of the shaft has been lined with the caisson sections, the jacks and supporting devices may be removed as the shoe 26 now rests on the shoulder 12 or on the bottom of the shaft. Before this is done, the annular space between the outer periphery of the caisson sections and the periphery of the excavation is filled with a suitable grout to prevent the caisson from listing off center. The lowering bars here perform another beneficial function in that they serve to reinforce the grout an add to the strengthof the shaft lining.

As may be seen from the foregoing description, a method has been provided for lowering any desired number of caisson sections into a shaft whereby its sides are lined. The method permits the joints between adjacent caisson sections to be checked before they are lowered into the shaft thereby assuring that the shaft will be moistureproof. A simple and convenient apparatus is provided for carrying out this method, the apparatus including novel lowering bars that are used in cooperation with suitable jacking and supporting apparatus. It should be understood that various changes could be made in the apparatus described within the teaching of the present invention. For example, lowering devices other than hydraulic jacks could be used, as well as other supporting devices. The lowering barscould also take different shapes, the only requirement being The invention may be embodied in other specific forms not departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

We claim:

1. Apparatus for lining a shaft formed in the earth comprising:

a series of cylindrical shell sections positioned in said shaft, said shell sections being joined end to end and having diameters less than that of said shaft whereby an annular space is formed between the outer periphery of said sections and the periphery-of said shaft; l

a shoe joined to the first of said series of said shell sections, portions of said shoe protruding outwardly from said shell section into said annular space;

a plurality of-longitudinal members fastened to said protruding portions of said shoe, said members extending substantially parallel to the axis of said shell sections, each of said members comprising a plurality of interconnected sections;

first means supportingly positioned in said annular space, said means releasably suporting said members and being movable in a path parallel to the axis of said shell section and supported movement of said members in a first direction; and

second means positioned in said annular space, said second means being engageable with said members to prevent their movement in said first direction.

2. Apparatus for lining a shaft formed in the earth comprising:

a series of cylindrical shell sections positioned in said shaft, said shell sections being joined end to end and having diameters less than that of said shaft whereby an annular space is formed between the outer periphery of said sections and the periphery of said shafts; v

a shoe joined to the first of said series of shell sections, said shoe having portions protruding outwardly from said shell section into said annular space;

a plurality of longitudinal members fastened to said protruding portions of said shoe, said members extending from said shoe along the length of said series of sections substantially parallel to the axis of said sections, each of said members comprising a plurality of interconnected sections;

first means supportingly positioned in said annular space, said first means including means operable in a first position to engage and releasably support said members, said first means being operatively movable in a path parallel to the axis of said shell sections whereby said sections may be moved into said shaft when said engaging means is in said first position; and

second means positioned in said annular space, said second means being operable to engage said members whereby movement of said sections into said shaft is prevented.

3. Apparatus for lining a shaft formed in the earth comprising:

a series of cylindrical shell sections positioned in said shaft, said shell sections being joined end to end and having diameters less than that of said shaft whereby an annular space is formed between the outer periphery of said sections and the periphery of said shafts;

a shoe joined to the first of said series of shell sections, said shoe having portions protruding outwardly from said shell section into said annular space;

a plurality of longitudinal members fastened to said protruding portions of said shoe, said members extending from said shoe along the length of said series of sections substantially parallel to the axis of said sections, each of said members comprising a plurality of interconnected sections;

a plurality of movable means supportingly positioned in said annular space, each of said means being associated with one of said longitudinal members, each of said means including releasable support means operable in a first position to support its respective memher, said releasable support means being movable in a path parallel to the axis of said shell sections whereby said sections may be supportedly moved relative to said shaft when each of said support means is in said first position; and

a plurality of supporting means positioned in said annular space, each of said supporting means being associated with one of said longitudinal members, each of said supporting means including means operable to engage its respective member whereby movement of said sections into said shaft is prevented.

4. The apparatus of claim 3 wherein said longitudinal members have portions having enlarged cross-sectional areas positioned along their length, and each of said movable means and supporting means are provided with an opening through which its respective member travels, the opening being insufficient to permit passage of said enlarged area portion.

5. A method of lining a shaft in the earth with a series of shell sections placed end to end, the first of which rests upon a shoe to which isfastened a plurality of lowering bars, comprising:

resting the first shell section on the shoe,

supporting the lowering bars from the earth independently of the shell section, and thereby maintaining the shoe and shell section in position over the shaft,

lowering the bars, and thereby lowering the shoe and shell section into the shaft,

terminating the lowering movement,

positioning another shell section on the first shell section while supported by the shoe and bars to form a joint therebetween adjacent the top of the shaft, adding additional sections to the lowering bars to lengthen them but without connecting them to the shell sections,

supporting the said additional sections of the lowering bars from the earth,

lowering the bars, shoe and shell sections,

and repeating the steps of adding a shell section, adding lowering bar sections without connecting them to the shell sections, and lowering, until the shaft is lined to the desired depth.

6. A method of lining a shaft in the earth with a series of cylindrical shell sections placed end to end, the first of which rests upon a shoe to which is fastened a plurality of lowering bars, comprising:

resting the first cylindrical shell section on the shoe,

supporting the lowering bars from the earth independently of the shell section, and thereby maintaining the shoe and shell section in position over the shaft,

lowering the bars, and thereby lowering the shoe and shell section into the shaft, terminating the lowering movement, resting another shell section on the first shell section while supported by the shoe and bars and forming a joint between them adjacent the top of the shaft,

adding additional sections to the lowering bars to lengthen them but without connecting them to the shell sections,

supporting the said additional sections of the lowering bars from the earth,

lowering the bars, shoe and shell sections,

and repeating the steps of adding a shell section, add- 7 ing lowering bar sections without connecting them to the shell sections, and lowering, until the shaft is lined to the desired depth.

7. A method of lining a shaft in the earth with a series of cylindrical concrete shell sections placed end to end, the first of which rests upon a metal shoe to which is fastened a plurality of metal lowering bars, comprising:

resting the first concrete shell section on the metal shoe, I

supporting the metal lowering bars from the earth independently of the concrete shell section, and thereby maintaining the shoe 'and shell section in position over the shaft,

' lowering the bars, and thereby lowering the shoe and shell section into the shaft,

terminating the lowering movement,

resting another shell section on the first shell section while supported by the shoe and bars and forming a joint between them adjacent the top of the shaft,

adding additional sections to the lowering bars to supporting the said additional sections 8 lengthen them but without connecting them to the shell sections,

of the lowering bars from the earth, lowering the bars, shoe and shell sections, and repeating the steps of adding a shell section, adding lowering bar sections without connecting them to the shell sections, and lowering, until the shoe rests on the bottom of the shaft.

References Cited by the Examiner UNITED STATES PATENTS 987,266 3/1911 Smith. 2,342,243 2/ 1944 Brizay.

2,932,486 4/1960 Suderow 61-465 X 2,966,336 12/1960 Owen 6146.5 X

FOREIGN PATENTS 658,928 1/ 1929 France. 1,095,409 12/ 1954 France.

EA-RL J. WITMER, Primary Examiner. 

1. APPARATUS FOR LINING A SHAFT FORMED IN THE EARTH COMPRISING: A SERIES OF CYLINDRICAL SHELL SECTIONS POSITIONED IN SAID SHAFT, SAID SHELL SECTIONS BEING JOINED END TO END AND HAVING DIAMETERS LESS THAN THAT OF SAID SHAFT WHEREBY AN ANNULAR SPACE IS FORMED BETWEEN THE OUTER PERIPHERY OF SAID SECTIONS AND THE PERIPHERY OF SAID SHAFT; A SHOE JOINED TO THE FIRST OF SAID SERIES OF SAID SHELL SECTIONS, PORTIONS OF SAID SHOE PROTRUDING OUTWARDLY FROM SAID SHELL SECTION INTO SAID ANNULAR SPACE; A PLURALITY OF LONGITUDINAL MEMBERS FASTENED TO SAID PROTRUDING PORTIONS OF SAID SHOE, SAID MEMBERS EXTENDING SUBSTANTIALLY PARALLEL TO THE AXIS OF SAID 